[Mitral stenosis and the problem of critical constriction in blood circulation].

The results of a combined echocardiographic study of 127 patients with mitral stenosis are reviewed. Echocardiographic and hemodynamic parameters are divided into 3 groups with respect to the severity of mitral stenosis. A relationship is demonstrated between mitral opening area and diastolic pressure gradient, as evidenced by dopplerography. The definition of critical mitral stenosis is given. A classification of the severity of mitral stenosis on the basis of two-dimensional echocardiography is offered, that provides indications for surgery.